In the same general area is Recreation Depot. There's a hobby shop in the back of the store that principally sells R/C planes/cars/helicopters/etc but he does have a display of Estes rockets and a pretty decent selection of LPR motors. He's well stocked for all the little hardware things you might need, like bolts, glues, FG, etc. It's on county Rt. 541 just south of the Rt. 38 intersection, directly across 541 from Lowe's. It's in a small shopping plaza with other professional buildings.
You might also want to look at AAA Hobbies. It's at 706 North White Horse Pike (Rt. 30) in Magnolia. He's got a pretty eclectic mix of LPR and MPR rockets from Estes, Custom Rockets, Quest, Edmonds, Madcow and more that I can't remember. He mostly carries LPR motors, but I think he still has some MPR stuff but it might not be on display.
Good luck!